Which of the choices is a right triangle ?

C - because root 80 squared is 80
And 80 = 8 squared + 4 squared
Because of the Pythagorean’s theorem which is c^2 = a^2 + b^2

Hello! i hope this
since the cosine is the ratio of the adjacent side to the hypotenuse, you can see that cos 60° = ½. answer. according to the property of cofunctions (topic 3), sin 30° is equal to cos 60°. sin 30° = ½.